Current carrier scaffolds for cell mass production may be divided into two categories, one being natural materials such as collagen, chitosan, gelatin or the like, and the other being synthetic materials such as polycaprolactone (PCL), polystyrene (PS), polypropylene (PP), poly(lactic-co-glycolic acid) (PLGA) or the like. The natural materials are mostly materials derived from animal sources. Although the materials derived from animal sources have lower cytotoxicity and higher biocompatibility, they may carry undetectable animal contaminants. Therefore, the current trend is toward reducing or even eliminating the use of the materials derived from animal sources to reduce the risk of contamination.
In addition, among current commercially available cell carriers, all the synthetic materials except for alginate-based related products are difficult to degrade, thus causing challenges in recovering the cells. Since the alginate-based related products require a high concentration of calcium ions during cell culture, the cells may be damaged or a tendency to differentiation may be induced in some certain cells (e.g., mesenchymal stem cells). In addition, during degradation of alginate, it is necessary to use a calcium ion chelator, and improper usage thereof is very likely to cause damage to the cells. In addition, there is still room for improvement in key techniques for cell collection carrier scaffolds. Thus, current cell mass production technology still remains at a conventional two-dimensional flat plate culture method, and the process cannot be adapted to larger scale production.
Therefore, to find a carrier material suitable for rapid and mass growth of cells and yet devoid of animal contaminants and to enhance cell recovery rate and cell quality are both issues that researchers are eager to solve.